Tapes of this general kind are combined in long lengths to provide rolls of diaper tab stock. A diaper manufacturer then dispenses and transversely severs the combined tapes in a sequential manner to form individual diaper tabs and apply them to the edges of diapers being manufactured. This operation forms the permanent "factory" joint between each individual refastenable tab and its associated diaper. When the tab is used to fasten the diaper on a user, the tab's free end is deployed for adhesive fastening directly to another part of the diaper, or to a reinforcing tape (also called a target tape or a landing zone tape) carried on such other part of the diaper. Fastening establishes a temporary "user" joint between the tab and such other part of the diaper.
When applied to a diaper, the fastening tape portion of the tab is generally folded around the diaper edge in a storage position, with the free end of the fastening tape portion carried on a release coating provided on the outside of the release tape portion of the tab. The free end of the fastening tape portion is lifted from the release coating to deploy the tab for fastening. In this deployed condition of the tab, the fastening tape portion extends from its distal end back past the edge of the diaper and is adhesively anchored to the backsheet of polyethylene or the like at the outside face of the diaper. Beyond the diaper edge, the release tape portion of the tab is joined to the fastening tape portion at a branching point. From this branching point, the release tape portion of the tab extends over and is adhesively anchored to the facesheet of moisture-pervious nonwoven fabric or the like at the inside face of the diaper. Tabs of this branching configuration type are of several different sub-types, including direct Y-bond, Y-bond junction, peel junction, and Adam (an acronym derived from "Area Divarication Adhesive Means", the title of Reed et al. U.S. Pat. No. 3,833,456 of common assignee, now expired). These various sub-types are referred to below in more detail.
The bond between the fastening tape and release tape portions of the tab at the tab's branching point strongly contributes to the distribution and absorption of tab tension forces imposed at the factory joint of the tab when the product is in use. If the bond at the branching point yields or fails, these forces are not properly distributed, and can destroy the relatively weak elements of the diaper to which the tab is attached at its factory joint, i.e., the thin backsheet of polyethylene or the like at the outside face of the diaper and the thin facesheet of moisture-pervious unwoven fabric or the like at the inside face.